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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 34 |
| 5 | 159 |
| 6 | 730 |
| 7 | 3579 |
| 8 | 17762 |
| 9 | 90538 |
| 10 | 467796 |
| 11 | 2452727 |
| 12 | 12997554 |
| 13 | 69549847 |
| 14 | 375159290 |
| 15 | 2038068813 |
| 16 | 11140256754 |
| 17 | 61227097438 |
| 18 | 338140106124 |
| 19 | 1875581756078 |
| 20 | 10444142352812 |
| 21 | 58364192607047 |
| 22 | 327203347219250 |
| 23 | 1839778650617309 |
| 24 | 10372512509521074 |
[0,1,2,9,34,159,730,3579,17762,90538,467796, 2452727,12997554,69549847,375159290,2038068813, 11140256754,61227097438,338140106124, 1875581756078,10444142352812,58364192607047, 327203347219250,1839778650617309, 10372512509521074] |